On unitarity of the hypergeometric amplitude

Journal Article · 21 February 2025 · Journal of High Energy Physics (Online)

DOI: https://doi.org/10.1007/jhep02(2025)145 · OSTI ID:2521008

Mansfield, Gareth  ^[1]; Spradlin, Marcus  ^[1]

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1. Brown University, Providence, RI (United States)

The hypergeometric amplitude is a one-parameter deformation of the Veneziano amplitude for four-point tachyon scattering in bosonic string theory that is consistent with S-matrix bootstrap constraints. In this article we construct a similar hypergeometric generalization of the Veneziano amplitude for type-I superstring theory. We then rule out a large region of the (r, m², D) parameter space as non-unitary, and establish another large subset of the (r, m², D) parameter space where all of the residue’s partial wave coefficients are positive. We also analyze positivity in various limits and special cases. As a corollary to our analysis, we are able to directly demonstrate positivity of a wider set of Veneziano amplitude partial wave coefficients than what has been presented elsewhere.

• Research Organization: Brown University, Providence, RI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: SC0010010
• OSTI ID: 2521008
• Journal Information: Journal of High Energy Physics (Online), Journal Name: Journal of High Energy Physics (Online) Journal Issue: 2 Vol. 2025; ISSN 1029-8479
• Publisher: Springer NatureCopyright Statement
• Country of Publication: United States
• Language: English